Does Blender 2.8 still have skeleton sketching?
Blender 2.8 doesn't have this feature anymore. The reason is that the feature was rather obscure, not used by many people and the implementation had several bugs. You can see the discussion in ticket T52809 in the official bug tracker. The commit rB36773e35f6009693562330137435271922758b95 removed this feature back in April 2018 from the master branch.